The present invention relates to a magnetic disk drive substantially free from an off-track problem ascribable to varying ambient temperature.
Electronic apparatuses including computers and word processors write and read data out of recording media by use of various kinds of magnetic recording/reproducing or magnetic recording implementations. Among them, a magnetic disk drive operable with a magnetic disk usually includes a rotary carriage on which a magnetic head is mounted in such a manner as to face the opposite sides of magnetic disks. As the disks are rotated at high speed, the head is moved away from the surfaces of the disks by a small distance by the resulting pneumatic pressure to thereby magnetically write or read data in or out of the disks. The head is made up of data heads for the write-in and read-out of data and servo heads for positioning the data heads. Specifically, the carriage reads a positioning pattern stored in the disks by the servo heads to thereby position the data heads. A current trend in the magnetic recording and playback art is toward a magnetic disk drive having a greater capacity. To increase the capacity of a disk drive, it is necessary to increase the recording density by increasing either the bit density or the track density. The track width available today is as small as 15 microns.
Generally, an electronic apparatus using a magnetic disk drive is used under varying ambient conditions, especially varying ambient temperature. It follows that the various members constituting the disk drive and each having a particular coefficient of thermal expansion deform in different manners in response to a change in ambient temperature. Then, the data heads positioned by the servo heads are deviated from the target tracks, i.e., go off-track, failing to read data out of the tracks of interest.